There are just five species of the kalkvygies (chalk mesembs) in the genus Titanopsis. They grow in patches of arid land in the centre and west of South Africa and in the south of Namibia. The chalk connection comes from the raised calcium-filled warts on the leaf surfaces. Titanos means chalk and opsis means appearance. The leaf tips of Titanopsis calcarea to be seen in this photo, give good examples of those warty ridges, definitive feature of a kalkvygie. This species has warts of a variety of sizes mixed up on the leaf (and sepal) surfaces.
Another colloquial Afrikaans name of this vygie, skilpadvoetjies (little tortoise feet), the appearance of which the locals in the Kalahari and Namaqualand know very well, can also be understood from a look at the leaves. The flowers of these mesembs only open in the afternoon and close again at sunset. The flowers have single whorls of yellow or amber petals. There is an erect cone of stamens and staminodes in the centre of the flower. The fruit capsules that follow are divided into six locules, covered by light brown membranes.
This plant is found in the northern Karoo west of Kimberley on limestone outcrops (www.cactus-art.biz; Smith, et al, 1998).